There are known devices for drawing small quantities of liquid from bottles, which are called cylinder and piston droppers and which are also frequently combined directly with the stoppers of bottles.
The invention relates to an improved embodiment of these types of dropper devices, to achieve particular objects and advantages which will be made clear by the following text. In particular, by using the device according to the invention it is possible to enable even sightless persons to perceive the quantity of liquid sucked up by the cylinder and piston (in other words, syringe) system, or dispensed by said system. Advantages with respect to construction and assembly are also obtained, together with easier handling and possible elimination of components, such as rubber or other, which may cause a risk of contamination.
This device for drawing liquid from a bottle characteristically has in the stem a series of impressionsxe2x80x94in indented or relief formxe2x80x94which permit tactile perception and in certain cases permit the perception of the position of the piston with respect to the cylinder even by persons without sight.
Said impressions may also interact with at least one elastic tongue formed in the stopper, which clicks whenever an impression moves past, both during the stroke in the suction phase and during the reverse stroke in the dispensing phase. In this way it is possible to also provide auditory perception for persons without sight.
The device may comprise a plurality of elastic tongues distributed around the stem of the piston, which facilitates the insertion of the piston into the cylinder through the stopper. The insertion of the piston into the stopper is also facilitated by a conical funnel-shaped profile. The piston may be formed by molding from the same material as the stem. The possibility of inserting the stem and the piston means that the operator""s end of the piston stem can be developed with an expansion which facilitates the grasping and operation of the piston.
The inner end of the stem may have an extension, forming an auxiliary stopper capable of interacting with a seat formed for it in the base of the cylinder, to seal the seat when the bottle is in the closed condition.
The elastic tongue or tongues can be formed in an extension of the stopper in the form of a sleeve which surrounds the stem of the piston.
The invention will be more clearly understood from the description and the attached drawing, which shows a non-restrictive practical example of the invention.